In the discussion of the background that follows, reference is made to certain structures and methods. However, the following references should not be construed as an admission that these structures and methods constitute prior art. Applicants expressly reserve the right to demonstrate that such structures and methods do not qualify as prior art.
Replacement human blood is vital to medical treatment. Many medical treatments including many operations would not be possible without blood being available to replace blood lost during medical procedures and injuries. Blood, contains cellular components, principally red blood cells (“erythrocytes”), platelets (“thrombocytes”) and white blood cells (“leukocytes”), suspended in plasma.
One problem in supplying replacement blood is that it is perishable. As soon as blood is collected, red cells within the blood may acquire “storage lesions,” which may reduce the effectiveness of these cells to deliver oxygen to tissue. Moreover, freezing and thawing may damage cells and reduce their effectiveness. The blood may also acquire inflammatory factors especially when white cells are allowed to remain. The blood may also contain infectious agents that may proliferate, especially when blood components are stored at room temperature as is the case for platelets. For these reasons, fresh blood is more effective and, in practice is preferred over older blood. Regulatory agencies have set the time period for using red blood cells to forty-two (42) days after collection, and have set the time period for using platelets to only five (5) days (or seven days provided special storage conditions are ensured) due to the risk of proliferation of bacteria as platelets are stored at room temperature. Expired blood components are no longer suitable for human use. In the United States of America, approximately 400 thousand of 1.675 million units of red blood cells collected, and approximately 200 thousand of 1.810 million units of (single donor) platelets collected expire before use.
Another problem in supplying replacement blood is that the replacement blood is typically matched to the recipient's blood type only with respect to an abbreviated blood type such as A+, AB−, or O−, which indicates the presence (“A”, “B” or “AB”) or absence (“O”) of the antigens within the ABO blood group system and “+” or “−”, which indicates the presence or absence (by traditional “agglutination” testing) of the D antigen, a constituent of the RH blood group system. However, the International Society of Blood Transfusion to date has defined thirty (30) blood group systems each of which may include multiple antigens.
The set of antigens expressed on an individual's blood cells is referred to herein as an attribute profile or an antigen profile. Any of the antigens associated with molecules on cell surfaces of replacement blood cells may cause the recipient's immune system to treat the replacement blood as foreign if the recipient's own blood cells do not have the same antigens as the replacement blood antigens. This may lead to immune reactions and adverse clinical events. Adverse immune reactions may be mild and have no significant effect on the recipient or may be severe and life threatening. Seventy-two thousand (72,000) adverse transfusion-related events were reported in 2006. Determining the identity of individual antigens, or the identity of an entire set of antigens of a replacement blood unit may be prohibitively time consuming and expensive. Often, in the United States of America, routine antigen testing prior to red blood cell transfusion is limited to the principal antigens, A, B and D, and typically is omitted altogether prior to platelet transfusion.
Another problem in supplying replacement blood is the way in which blood is collected and distributed. Blood units are often collected from donors residing in a given local area, and are distributed to local hospitals that perform the surgical or other procedures requiring transfusion support. The cost of a blood unit may vary significantly by geographic area for many reasons including labor costs and the availability of donors. As blood units often are only distributed locally or regionally shortages may occur in some locations while surpluses occur in other locations. Additionally, it may be prohibitively time consuming or expensive for a health care provider to locate and procure a blood unit with particular attributes.
These same problems are often common problems for perishable items with attributes that may require testing to determine the attribute profile of the perishable items prior to use.